Combination Vehicles

Question 1

Where should tractor be when you inspect landing gear after uncoupling the trailer?

Answer 1

With the tractor frame under the trailer

Question 2

While driving behind another vehicle under good conditions you should allow at least one second between your vehicle and the vehicle ahead for each ____ (how many) feet of your vehicle length?

Answer 2

10

Question 3

There are two things that a driver can do to prevent a rollover. They are: (1) keep the cargo as close to the ground as possible; and (2):

Answer 3

Go slow around turns

Question 4

The air brake leakage rate for a combination vehicle (engine off, brakes off)should be less than ___ psi per minute.

Answer 4

3

Question 5

The safest way to make a turn without entering another traffic lane is:

Answer 5

You should turn wide as you complete the turn

Question 6

The higher the center of gravity of your truck, the:

Answer 6

Easier to turn over

Question 7

If the service line comes apart while you are driving a combination vehicle but the emergency line stays together, what will hapen right away?

Answer 7

Nothing is likely to happen until you try to apply the brakes.

Question 8

Glad hands are usually connecting which lines?

Answer 8

Service and emergency air lines from the vehicle to the trailer

Question 9

A driver crosses the air lines when hooking up to an old trailer, what will happen?

Answer 9

If the trailer has no spring brakes, you could drive, but you wouldn’t have trailer brakes

Question 10

The hand valve should be used

Answer 10

To test the trailer brakes

Question 11

When driving a set of doubles it is necessary to close which shut-off valve in the last trailer?

Answer 11

Back

Question 12

If the service line comes apart while you are driving a combination vehicle but the emergency line stays together, what will happen right away?

Answer 12

Nothing is likely to happen until you try to apply the brakes

Question 13

You are about to back your tractor under a semi-trailer. The trailer is at the right height when the:

Answer 13

Trailer will be lifted slightly when the tractor backs under it

Question 14

Your emergency air line breaks or gets pulled apart while you are driving. The loss of pressure will cause the:

Answer 14

Emergency trailer brakes to come on

Question 15

If the brakes did not release when you pushed the trailer air supply valves you should:

Answer 15

Check air line connection

Question 16

Air brake equipped trailers made before 1975:

Answer 16

Often do not have spring brakes

Question 17

There are two things that a driver can do to prevent a rollover, (1.) go slow around turns, and (2.)

Answer 17

Keep the cargo as close to the ground as possible

Question 18

After connecting the air lines, but before backing under the trailer you should

Answer 18

Supply air to the trailer system, the pull the air supply knob.

Question 19

Which part of the kingpin should the locking jaws close around?

Answer 19

The shank

Question 20

How much space should be allowed between upper and lower fifth wheel after coupling?

Answer 20

Nothing

Question 21

You have pushed the trailer air supply valve. You should not back a tractor under a trailer until the whole air system is

Answer 21

At normal pressure

Question 22

You are coupling a tractor to a semi-trailer. You have conected the airline. Before backing under the trailer you should

Answer 22

Supply air to the trailer system, then pull out the air supply knob

Question 23

You are coupling a tractor to a semi-trailer and have backed up but are not under it. What should you hook up before backing under?

Answer 23

The emergency and service lines

Question 24

Tractor with a _______ trailer requires the shortest amount of stopping distance.

Answer 24

Fully loaded

Question 25

After you have couple the trailer you should raise the landing gear by using

Answer 25

Low gear

Question 26

You supply air to the trailer tanks by

Answer 26

Pushing in the trailer air supply valve

Question 27

Why should you be sure that the fifth wheel plate is greased as required?

Answer 27

To prevent steering problems

Question 28

When connecting the glad hands, press the two seals with the coupler together at what degree to each other?

Answer 28

90 Degrees

Question 29

Which of these statements is true?

Answer 29

Bobtail tractors can take longer to stop than a combination vehicle loaded to maximum gross weight.

Question 30

Why should you lock the tractor glad hands to each other (or dummy couplers) when you are not towing a trailer?

Answer 30

It will keep dirt or water out of the lines

Question 31

When backing a tractor under a trailer you should

Answer 31

Always use the lowest reverse gear

Question 32

After the trailer has been coupled to the tractor, the tractor protection control valve should be placed in what position?

Answer 32

Normal

Question 33

The fifth wheel locking lever is not locked after the jaws close around the kingpin. This means that:

Answer 33

The coupling is not right and should be fixed before driving the coupled unit.

Question 34

Off-tracking or cheating causes which of these to follow the wider pass while making a turn?

Answer 34

Tractor towing a 45 foot trailer

Question 35

The iron trailer supports are up and the trailer is resting on the tractor. Make sure:

Answer 35

There is enough clearance between the tractor frame and landing gear.

Question 36

When you are uncoupling a loaded trailer you should lower the landing gear until it

Answer 36

Makes firm contact with the ground, then crank in a low gear a few extra turns.

Question 37

What will happen if the air lines are crossed when you hook up to an old trailer?

Answer 37

If the trailer has no spring brakes, you could drive away but wouldn't have any trailer brakes

Question 38

To stop a trailer skid you should

Answer 38

Release the service brakes

Question 39

If you cannot make a turn without entering another traffic lane

Answer 39

You should turn wide as you complete the turn

Question 40

The air lines on combination vehicles are often colored to prevent them from mixing up. The emergency line is___, and the service line is ___.

Answer 40

Red, Blue

Question 41

The air leakage rate for a combination vehicle (engine off, brakes on) should be less than ___ psi per minute.

Answer 41

4

Question 42

Compared to a straight truck or bus there are ___ things to inspect in combination vehicles.

Answer 42

More

Question 43

When checking the trailer emergency brakes, the tractor protection control valve should be placed in what position?

Answer 43

Emergency

Question 44

In normal driving, some drivers use the hand valve before the brake pedal to prevent a jackknife. Which of the statements is true?

Answer 44

It should not be done

Question 45

While checking if the trailer is securely coupled to the trailer, the landing gears should be

Answer 45

Slightly raised

Question 46

Air and electrical lines from the tractor to the trailer should be

Answer 46

Secured but with enough loop to turn

Question 47

You have a major leak in the service line and you put on the brakes. Service air will escape and cause the

Answer 47

Trailer emergency brakes to come on

Question 48

When you get ready to back under a semi-trailer you should line up

Answer 48

Directly in front of the trailer.

Question 49

Off-tracking or cheating causes which of these to follow the wider pass while making a turn?

Answer 49

Tractor towing a 45 foot trailer

Question 50

After you lock the kingpin into the fifth wheel, you should check the connection by

Answer 50

Pulling the tractor ahead gently with the trailer brakes locked

Question 51

When should you use the hand valve to park a combination vehicle?

Answer 51

Never

Question 52

You have coupled with a semitrailer. Where should you put the iron trailer supports before driving away?

Answer 52

Fully raised with the crank handle secured in its bracket.

Question 53

The safety catch for the fifth wheel locking lever must be ____ for a coupling to be complete.

Answer 53

Over the locking lever

Question 54

After you supply air to the trailer, make sure the air lines are not crossed and the trailer brakes are working. This is done by

Answer 54

Applying and releasing the trailer brakes and listening for the sound of the brake

Question 55

Before you back under a trailer, make sure that

Answer 55

The trailer brakes are locked

Question 56

How should you test the tractor-semi-trailer connection for security?

Answer 56

Pull gently forward in low gear against the locked trailer brakes then look at it carefully.

Question 57

The front trailer supports are up and the trailer is resting on the tractor. Make sure

Answer 57

There is enough clearance between the top of the tractor tires and nose of the trailer and that there is enough clearance between the tractor frame and the landing gear

Question 58

To unlock the fifth wheel the locking lever should be placed in the ____ position.

Answer 58

Open

Question 59

The tractor protection valve will close and the trailer emergency brakes will come on when there is a major leak in the ____ brake line

Answer 59

Emergency

Question 60

When coupling, the proper position of the fifth wheel is

Answer 60

Tilted down towards the end of the trailer

Question 61

What gear should the tractor engine be in after you uncouple the trailer and are inspecting the trailer supports?

Answer 61

Neutral

Question 62

When uncoupling the trailer, after you shut off the trailer air supply and lock the trailer, you should:

Answer 62

Back up gently to ease pressure on the fifth wheel

Question 63

You are driving a combination vehicle when the trailer breaks away, pulling apart both air lines. You expect the trailer brakes to come on and

Answer 63

The tractor protection valve to close